3 * Copyright (c) 2001 Fabrice Bellard.
5 * This library is free software; you can redistribute it and/or
6 * modify it under the terms of the GNU Lesser General Public
7 * License as published by the Free Software Foundation; either
8 * version 2 of the License, or (at your option) any later version.
10 * This library is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 * Lesser General Public License for more details.
15 * You should have received a copy of the GNU Lesser General Public
16 * License along with this library; if not, write to the Free Software
17 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
29 typedef struct AVIStream {
30 int64_t frame_offset; /* current frame (video) or byte (audio) counter
31 (used to compute the pts) */
37 int sample_size; /* size of one sample (or packet) (in the rate/scale sense) in bytes */
39 int64_t cum_len; /* temporary storage (used during seek) */
41 int prefix; ///< normally 'd'<<8 + 'c' or 'w'<<8 + 'b'
53 DVDemuxContext* dv_demux;
56 static int avi_load_index(AVFormatContext *s);
57 static int guess_ni_flag(AVFormatContext *s);
60 static void print_tag(const char *str, unsigned int tag, int size)
62 printf("%s: tag=%c%c%c%c size=0x%x\n",
71 static int get_riff(AVIContext *avi, ByteIOContext *pb)
74 /* check RIFF header */
77 if (tag != MKTAG('R', 'I', 'F', 'F'))
79 avi->riff_end = get_le32(pb); /* RIFF chunk size */
80 avi->riff_end += url_ftell(pb); /* RIFF chunk end */
82 if (tag != MKTAG('A', 'V', 'I', ' ') && tag != MKTAG('A', 'V', 'I', 'X'))
88 static int read_braindead_odml_indx(AVFormatContext *s, int frame_num){
89 AVIContext *avi = s->priv_data;
90 ByteIOContext *pb = &s->pb;
91 int longs_pre_entry= get_le16(pb);
92 int index_sub_type = get_byte(pb);
93 int index_type = get_byte(pb);
94 int entries_in_use = get_le32(pb);
95 int chunk_id = get_le32(pb);
96 int64_t base = get_le64(pb);
97 int stream_id= 10*((chunk_id&0xFF) - '0') + (((chunk_id>>8)&0xFF) - '0');
101 int64_t last_pos= -1;
103 // av_log(s, AV_LOG_ERROR, "longs_pre_entry:%d index_type:%d entries_in_use:%d chunk_id:%X base:%Ld\n",
104 // longs_pre_entry,index_type, entries_in_use, chunk_id, base);
106 if(stream_id > s->nb_streams || stream_id < 0)
108 st= s->streams[stream_id];
116 if(index_type && longs_pre_entry != 2)
121 for(i=0; i<entries_in_use; i++){
123 int64_t pos= get_le32(pb) + base - 8;
124 int len = get_le32(pb);
128 //av_log(s, AV_LOG_ERROR, "pos:%Ld, len:%X\n", pos, len);
129 if(last_pos == pos || pos == base - 8)
130 avi->non_interleaved= 1;
132 av_add_index_entry(st, pos, ast->cum_len, len, 0, key ? AVINDEX_KEYFRAME : 0);
135 ast->cum_len += len / ast->sample_size;
142 offset = get_le64(pb);
143 get_le32(pb); /* size */
144 duration = get_le32(pb);
147 url_fseek(pb, offset+8, SEEK_SET);
148 read_braindead_odml_indx(s, frame_num);
149 frame_num += duration;
151 url_fseek(pb, pos, SEEK_SET);
157 static void clean_index(AVFormatContext *s){
160 for(i=0; i<s->nb_streams; i++){
161 AVStream *st = s->streams[i];
162 AVIStream *ast = st->priv_data;
163 int n= st->nb_index_entries;
164 int max= ast->sample_size;
165 int64_t pos, size, ts;
167 if(n != 1 || ast->sample_size==0)
170 while(max < 1024) max+=max;
172 pos= st->index_entries[0].pos;
173 size= st->index_entries[0].size;
174 ts= st->index_entries[0].timestamp;
176 for(j=0; j<size; j+=max){
177 av_add_index_entry(st, pos+j, ts + j/ast->sample_size, FFMIN(max, size-j), 0, AVINDEX_KEYFRAME);
182 static int avi_read_header(AVFormatContext *s, AVFormatParameters *ap)
184 AVIContext *avi = s->priv_data;
185 ByteIOContext *pb = &s->pb;
186 uint32_t tag, tag1, handler;
187 int codec_type, stream_index, frame_period, bit_rate;
188 unsigned int size, nb_frames;
191 AVIStream *ast = NULL;
192 int xan_video = 0; /* hack to support Xan A/V */
194 avi->stream_index= -1;
196 if (get_riff(avi, pb) < 0)
209 print_tag("tag", tag, size);
213 case MKTAG('L', 'I', 'S', 'T'):
214 /* ignored, except when start of video packets */
217 print_tag("list", tag1, 0);
219 if (tag1 == MKTAG('m', 'o', 'v', 'i')) {
220 avi->movi_list = url_ftell(pb) - 4;
221 if(size) avi->movi_end = avi->movi_list + size;
222 else avi->movi_end = url_fsize(pb);
224 printf("movi end=%Lx\n", avi->movi_end);
229 case MKTAG('d', 'm', 'l', 'h'):
231 url_fskip(pb, size + (size & 1));
233 case MKTAG('a', 'v', 'i', 'h'):
235 /* using frame_period is bad idea */
236 frame_period = get_le32(pb);
237 bit_rate = get_le32(pb) * 8;
239 avi->non_interleaved |= get_le32(pb) & AVIF_MUSTUSEINDEX;
241 url_fskip(pb, 2 * 4);
245 st = av_new_stream(s, i);
249 ast = av_mallocz(sizeof(AVIStream));
254 url_fskip(pb, size - 7 * 4);
256 case MKTAG('s', 't', 'r', 'h'):
260 handler = get_le32(pb); /* codec tag */
262 print_tag("strh", tag1, -1);
264 if(tag1 == MKTAG('i', 'a', 'v', 's') || tag1 == MKTAG('i', 'v', 'a', 's')){
266 * After some consideration -- I don't think we
267 * have to support anything but DV in a type1 AVIs.
269 if (s->nb_streams != 1)
272 if (handler != MKTAG('d', 'v', 's', 'd') &&
273 handler != MKTAG('d', 'v', 'h', 'd') &&
274 handler != MKTAG('d', 'v', 's', 'l'))
277 ast = s->streams[0]->priv_data;
278 av_freep(&s->streams[0]->codec->extradata);
279 av_freep(&s->streams[0]);
281 avi->dv_demux = dv_init_demux(s);
284 s->streams[0]->priv_data = ast;
285 url_fskip(pb, 3 * 4);
286 ast->scale = get_le32(pb);
287 ast->rate = get_le32(pb);
288 stream_index = s->nb_streams - 1;
289 url_fskip(pb, size - 7*4);
293 if (stream_index >= s->nb_streams) {
294 url_fskip(pb, size - 8);
295 /* ignore padding stream */
296 if (tag1 == MKTAG('p', 'a', 'd', 's'))
300 st = s->streams[stream_index];
302 st->codec->stream_codec_tag= handler;
304 get_le32(pb); /* flags */
305 get_le16(pb); /* priority */
306 get_le16(pb); /* language */
307 get_le32(pb); /* initial frame */
308 ast->scale = get_le32(pb);
309 ast->rate = get_le32(pb);
310 if(ast->scale && ast->rate){
311 }else if(frame_period){
313 ast->scale = frame_period;
318 av_set_pts_info(st, 64, ast->scale, ast->rate);
320 ast->cum_len=get_le32(pb); /* start */
321 nb_frames = get_le32(pb);
324 st->duration = nb_frames;
325 get_le32(pb); /* buffer size */
326 get_le32(pb); /* quality */
327 ast->sample_size = get_le32(pb); /* sample ssize */
328 // av_log(NULL, AV_LOG_DEBUG, "%d %d %d %d\n", ast->rate, ast->scale, ast->start, ast->sample_size);
331 case MKTAG('v', 'i', 'd', 's'):
332 codec_type = CODEC_TYPE_VIDEO;
334 ast->sample_size = 0;
336 case MKTAG('a', 'u', 'd', 's'):
337 codec_type = CODEC_TYPE_AUDIO;
339 case MKTAG('t', 'x', 't', 's'):
341 codec_type = CODEC_TYPE_DATA; //CODEC_TYPE_SUB ? FIXME
343 case MKTAG('p', 'a', 'd', 's'):
344 codec_type = CODEC_TYPE_UNKNOWN;
348 av_log(s, AV_LOG_ERROR, "unknown stream type %X\n", tag1);
351 ast->frame_offset= ast->cum_len * FFMAX(ast->sample_size, 1);
352 url_fskip(pb, size - 12 * 4);
354 case MKTAG('s', 't', 'r', 'f'):
356 if (stream_index >= s->nb_streams || avi->dv_demux) {
359 st = s->streams[stream_index];
361 case CODEC_TYPE_VIDEO:
362 get_le32(pb); /* size */
363 st->codec->width = get_le32(pb);
364 st->codec->height = get_le32(pb);
365 get_le16(pb); /* panes */
366 st->codec->bits_per_sample= get_le16(pb); /* depth */
368 get_le32(pb); /* ImageSize */
369 get_le32(pb); /* XPelsPerMeter */
370 get_le32(pb); /* YPelsPerMeter */
371 get_le32(pb); /* ClrUsed */
372 get_le32(pb); /* ClrImportant */
374 if(size > 10*4 && size<(1<<30)){
375 st->codec->extradata_size= size - 10*4;
376 st->codec->extradata= av_malloc(st->codec->extradata_size + FF_INPUT_BUFFER_PADDING_SIZE);
377 get_buffer(pb, st->codec->extradata, st->codec->extradata_size);
380 if(st->codec->extradata_size & 1) //FIXME check if the encoder really did this correctly
383 /* Extract palette from extradata if bpp <= 8 */
384 /* This code assumes that extradata contains only palette */
385 /* This is true for all paletted codecs implemented in ffmpeg */
386 if (st->codec->extradata_size && (st->codec->bits_per_sample <= 8)) {
387 st->codec->palctrl = av_mallocz(sizeof(AVPaletteControl));
388 #ifdef WORDS_BIGENDIAN
389 for (i = 0; i < FFMIN(st->codec->extradata_size, AVPALETTE_SIZE)/4; i++)
390 st->codec->palctrl->palette[i] = bswap_32(((uint32_t*)st->codec->extradata)[i]);
392 memcpy(st->codec->palctrl->palette, st->codec->extradata,
393 FFMIN(st->codec->extradata_size, AVPALETTE_SIZE));
395 st->codec->palctrl->palette_changed = 1;
399 print_tag("video", tag1, 0);
401 st->codec->codec_type = CODEC_TYPE_VIDEO;
402 st->codec->codec_tag = tag1;
403 st->codec->codec_id = codec_get_id(codec_bmp_tags, tag1);
404 if (st->codec->codec_id == CODEC_ID_XAN_WC4)
406 st->need_parsing = 2; //only parse headers dont do slower repacketization, this is needed to get the pict type which is needed for generating correct pts
407 // url_fskip(pb, size - 5 * 4);
409 case CODEC_TYPE_AUDIO:
410 get_wav_header(pb, st->codec, size);
411 if(ast->sample_size && st->codec->block_align && ast->sample_size % st->codec->block_align)
412 av_log(s, AV_LOG_DEBUG, "invalid sample size or block align detected\n");
413 if (size%2) /* 2-aligned (fix for Stargate SG-1 - 3x18 - Shades of Grey.avi) */
415 /* special case time: To support Xan DPCM, hardcode
416 * the format if Xxan is the video codec */
417 st->need_parsing = 1;
418 /* force parsing as several audio frames can be in
421 st->codec->codec_id = CODEC_ID_XAN_DPCM;
424 st->codec->codec_type = CODEC_TYPE_DATA;
425 st->codec->codec_id= CODEC_ID_NONE;
426 st->codec->codec_tag= 0;
432 case MKTAG('i', 'n', 'd', 'x'):
434 if(!url_is_streamed(pb)){
435 read_braindead_odml_indx(s, 0);
438 url_fseek(pb, i+size, SEEK_SET);
448 /* check stream number */
449 if (stream_index != s->nb_streams - 1) {
451 for(i=0;i<s->nb_streams;i++) {
452 av_freep(&s->streams[i]->codec->extradata);
453 av_freep(&s->streams[i]);
458 if(!avi->index_loaded && !url_is_streamed(pb))
460 avi->index_loaded = 1;
461 avi->non_interleaved |= guess_ni_flag(s);
462 if(avi->non_interleaved)
468 static int avi_read_packet(AVFormatContext *s, AVPacket *pkt)
470 AVIContext *avi = s->priv_data;
471 ByteIOContext *pb = &s->pb;
477 size = dv_get_packet(avi->dv_demux, pkt);
482 if(avi->non_interleaved){
483 int best_stream_index = 0;
484 AVStream *best_st= NULL;
486 int64_t best_ts= INT64_MAX;
489 for(i=0; i<s->nb_streams; i++){
490 AVStream *st = s->streams[i];
491 AVIStream *ast = st->priv_data;
492 int64_t ts= ast->frame_offset;
495 ts /= ast->sample_size;
496 ts= av_rescale(ts, AV_TIME_BASE * (int64_t)st->time_base.num, st->time_base.den);
498 // av_log(NULL, AV_LOG_DEBUG, "%Ld %d/%d %Ld\n", ts, st->time_base.num, st->time_base.den, ast->frame_offset);
502 best_stream_index= i;
505 best_ast = best_st->priv_data;
506 best_ts= av_rescale(best_ts, best_st->time_base.den, AV_TIME_BASE * (int64_t)best_st->time_base.num); //FIXME a little ugly
507 if(best_ast->remaining)
508 i= av_index_search_timestamp(best_st, best_ts, AVSEEK_FLAG_ANY | AVSEEK_FLAG_BACKWARD);
510 i= av_index_search_timestamp(best_st, best_ts, AVSEEK_FLAG_ANY);
512 // av_log(NULL, AV_LOG_DEBUG, "%d\n", i);
514 int64_t pos= best_st->index_entries[i].pos;
515 pos += best_ast->packet_size - best_ast->remaining;
516 url_fseek(&s->pb, pos + 8, SEEK_SET);
517 // av_log(NULL, AV_LOG_DEBUG, "pos=%Ld\n", pos);
519 assert(best_ast->remaining <= best_ast->packet_size);
521 avi->stream_index= best_stream_index;
522 if(!best_ast->remaining)
523 best_ast->packet_size=
524 best_ast->remaining= best_st->index_entries[i].size;
529 if(avi->stream_index >= 0){
530 AVStream *st= s->streams[ avi->stream_index ];
531 AVIStream *ast= st->priv_data;
534 if(ast->sample_size <= 1) // minorityreport.AVI block_align=1024 sample_size=1 IMA-ADPCM
536 else if(ast->sample_size < 32)
537 size= 64*ast->sample_size;
539 size= ast->sample_size;
541 if(size > ast->remaining)
542 size= ast->remaining;
543 av_get_packet(pb, pkt, size);
546 dstr = pkt->destruct;
547 size = dv_produce_packet(avi->dv_demux, pkt,
548 pkt->data, pkt->size);
549 pkt->destruct = dstr;
550 pkt->flags |= PKT_FLAG_KEY;
552 /* XXX: how to handle B frames in avi ? */
553 pkt->dts = ast->frame_offset;
554 // pkt->dts += ast->start;
556 pkt->dts /= ast->sample_size;
557 //av_log(NULL, AV_LOG_DEBUG, "dts:%Ld offset:%Ld %d/%d smpl_siz:%d base:%d st:%d size:%d\n", pkt->dts, ast->frame_offset, ast->scale, ast->rate, ast->sample_size, AV_TIME_BASE, avi->stream_index, size);
558 pkt->stream_index = avi->stream_index;
560 if (st->codec->codec_type == CODEC_TYPE_VIDEO) {
561 if(st->index_entries){
565 index= av_index_search_timestamp(st, pkt->dts, 0);
566 e= &st->index_entries[index];
568 if(index >= 0 && e->timestamp == ast->frame_offset){
569 if (e->flags & AVINDEX_KEYFRAME)
570 pkt->flags |= PKT_FLAG_KEY;
573 /* if no index, better to say that all frames
575 pkt->flags |= PKT_FLAG_KEY;
578 pkt->flags |= PKT_FLAG_KEY;
581 ast->frame_offset += pkt->size;
585 ast->remaining -= size;
587 avi->stream_index= -1;
598 memset(d, -1, sizeof(int)*8);
599 for(i=sync=url_ftell(pb); !url_feof(pb); i++) {
602 if (i >= avi->movi_end) {
604 url_fskip(pb, avi->riff_end - i);
605 avi->riff_end = avi->movi_end = url_fsize(pb);
614 size= d[4] + (d[5]<<8) + (d[6]<<16) + (d[7]<<24);
616 if( d[2] >= '0' && d[2] <= '9'
617 && d[3] >= '0' && d[3] <= '9'){
618 n= (d[2] - '0') * 10 + (d[3] - '0');
620 n= 100; //invalid stream id
622 //av_log(NULL, AV_LOG_DEBUG, "%X %X %X %X %X %X %X %X %lld %d %d\n", d[0], d[1], d[2], d[3], d[4], d[5], d[6], d[7], i, size, n);
623 if(i + size > avi->movi_end || d[0]<0)
627 if( (d[0] == 'i' && d[1] == 'x' && n < s->nb_streams)
629 ||(d[0] == 'J' && d[1] == 'U' && d[2] == 'N' && d[3] == 'K')){
631 //av_log(NULL, AV_LOG_DEBUG, "SKIP\n");
635 if( d[0] >= '0' && d[0] <= '9'
636 && d[1] >= '0' && d[1] <= '9'){
637 n= (d[0] - '0') * 10 + (d[1] - '0');
639 n= 100; //invalid stream id
643 if(n < s->nb_streams){
649 if( (st->discard >= AVDISCARD_DEFAULT && size==0)
650 /*|| (st->discard >= AVDISCARD_NONKEY && !(pkt->flags & PKT_FLAG_KEY))*/ //FIXME needs a little reordering
651 || st->discard >= AVDISCARD_ALL){
652 if(ast->sample_size) ast->frame_offset += pkt->size;
653 else ast->frame_offset++;
658 if( ((ast->prefix_count<5 || sync+9 > i) && d[2]<128 && d[3]<128) ||
659 d[2]*256+d[3] == ast->prefix /*||
660 (d[2] == 'd' && d[3] == 'c') ||
661 (d[2] == 'w' && d[3] == 'b')*/) {
663 //av_log(NULL, AV_LOG_DEBUG, "OK\n");
664 if(d[2]*256+d[3] == ast->prefix)
667 ast->prefix= d[2]*256+d[3];
668 ast->prefix_count= 0;
671 avi->stream_index= n;
672 ast->packet_size= size + 8;
673 ast->remaining= size;
677 /* palette changed chunk */
678 if ( d[0] >= '0' && d[0] <= '9'
679 && d[1] >= '0' && d[1] <= '9'
680 && ((d[2] == 'p' && d[3] == 'c'))
681 && n < s->nb_streams && i + size <= avi->movi_end) {
684 int first, clr, flags, k, p;
688 first = get_byte(pb);
690 if(!clr) /* all 256 colors used */
692 flags = get_le16(pb);
694 for (k = first; k < clr + first; k++) {
700 st->codec->palctrl->palette[k] = b + (g << 8) + (r << 16);
702 st->codec->palctrl->palette_changed = 1;
711 /* XXX: we make the implicit supposition that the position are sorted
713 static int avi_read_idx1(AVFormatContext *s, int size)
715 AVIContext *avi = s->priv_data;
716 ByteIOContext *pb = &s->pb;
717 int nb_index_entries, i;
720 unsigned int index, tag, flags, pos, len;
721 unsigned last_pos= -1;
723 nb_index_entries = size / 16;
724 if (nb_index_entries <= 0)
727 /* read the entries and sort them in each stream component */
728 for(i = 0; i < nb_index_entries; i++) {
730 flags = get_le32(pb);
733 #if defined(DEBUG_SEEK)
734 av_log(NULL, AV_LOG_DEBUG, "%d: tag=0x%x flags=0x%x pos=0x%x len=%d/",
735 i, tag, flags, pos, len);
737 if(i==0 && pos > avi->movi_list)
738 avi->movi_list= 0; //FIXME better check
739 pos += avi->movi_list;
741 index = ((tag & 0xff) - '0') * 10;
742 index += ((tag >> 8) & 0xff) - '0';
743 if (index >= s->nb_streams)
745 st = s->streams[index];
748 #if defined(DEBUG_SEEK)
749 av_log(NULL, AV_LOG_DEBUG, "%d cum_len=%d\n", len, ast->cum_len);
752 avi->non_interleaved= 1;
754 av_add_index_entry(st, pos, ast->cum_len, len, 0, (flags&AVIIF_INDEX) ? AVINDEX_KEYFRAME : 0);
756 ast->cum_len += len / ast->sample_size;
764 static int guess_ni_flag(AVFormatContext *s){
766 int64_t last_start=0;
767 int64_t first_end= INT64_MAX;
769 for(i=0; i<s->nb_streams; i++){
770 AVStream *st = s->streams[i];
771 int n= st->nb_index_entries;
776 if(st->index_entries[0].pos > last_start)
777 last_start= st->index_entries[0].pos;
778 if(st->index_entries[n-1].pos < first_end)
779 first_end= st->index_entries[n-1].pos;
781 return last_start > first_end;
784 static int avi_load_index(AVFormatContext *s)
786 AVIContext *avi = s->priv_data;
787 ByteIOContext *pb = &s->pb;
789 offset_t pos= url_ftell(pb);
791 url_fseek(pb, avi->movi_end, SEEK_SET);
793 printf("movi_end=0x%llx\n", avi->movi_end);
801 printf("tag=%c%c%c%c size=0x%x\n",
809 case MKTAG('i', 'd', 'x', '1'):
810 if (avi_read_idx1(s, size) < 0)
823 url_fseek(pb, pos, SEEK_SET);
827 static int avi_read_seek(AVFormatContext *s, int stream_index, int64_t timestamp, int flags)
829 AVIContext *avi = s->priv_data;
834 if (!avi->index_loaded) {
835 /* we only load the index on demand */
837 avi->index_loaded = 1;
839 assert(stream_index>= 0);
841 st = s->streams[stream_index];
842 index= av_index_search_timestamp(st, timestamp, flags);
846 /* find the position */
847 pos = st->index_entries[index].pos;
848 timestamp = st->index_entries[index].timestamp;
850 // av_log(NULL, AV_LOG_DEBUG, "XX %Ld %d %Ld\n", timestamp, index, st->index_entries[index].timestamp);
852 for(i = 0; i < s->nb_streams; i++) {
853 AVStream *st2 = s->streams[i];
854 AVIStream *ast2 = st2->priv_data;
859 if (st2->nb_index_entries <= 0)
862 // assert(st2->codec->block_align);
863 assert(st2->time_base.den == ast2->rate);
864 assert(st2->time_base.num == ast2->scale);
865 index = av_index_search_timestamp(
867 av_rescale(timestamp, st2->time_base.den*(int64_t)st->time_base.num, st->time_base.den * (int64_t)st2->time_base.num),
868 flags | AVSEEK_FLAG_BACKWARD);
872 if(!avi->non_interleaved){
873 while(index>0 && st2->index_entries[index].pos > pos)
875 while(index+1 < st2->nb_index_entries && st2->index_entries[index].pos < pos)
879 // av_log(NULL, AV_LOG_DEBUG, "%Ld %d %Ld\n", timestamp, index, st2->index_entries[index].timestamp);
880 /* extract the current frame number */
881 ast2->frame_offset = st2->index_entries[index].timestamp;
882 if(ast2->sample_size)
883 ast2->frame_offset *=ast2->sample_size;
887 dv_flush_audio_packets(avi->dv_demux);
889 url_fseek(&s->pb, pos, SEEK_SET);
890 avi->stream_index= -1;
894 static int avi_read_close(AVFormatContext *s)
897 AVIContext *avi = s->priv_data;
899 for(i=0;i<s->nb_streams;i++) {
900 AVStream *st = s->streams[i];
901 AVIStream *ast = st->priv_data;
903 av_free(st->codec->palctrl);
907 av_free(avi->dv_demux);
912 static int avi_probe(AVProbeData *p)
914 /* check file header */
915 if (p->buf_size <= 32)
917 if (p->buf[0] == 'R' && p->buf[1] == 'I' &&
918 p->buf[2] == 'F' && p->buf[3] == 'F' &&
919 p->buf[8] == 'A' && p->buf[9] == 'V' &&
920 p->buf[10] == 'I' && p->buf[11] == ' ')
921 return AVPROBE_SCORE_MAX;
926 AVInputFormat avi_demuxer = {